Method for continuously casting between stationary and moving surfaces



Aug. 29, 1967' A. w. SCRIBNER 3,3 2

METHOD FOR CONTINUOUSLY CASTING BETWEEN STATIONARY AND MOVING SURFACES Original Filed Oct. 30, 1963 United States Patent 3,338,295 METHOD FOR CONTINUOUSLY CASTING BE- ;WgEN STATIONARY AND MOVING SUR- A ES Albert W. Scribner, 6 Country Club Road, Darien, Conn. 06820 Original application Oct. 30, 1963, Ser. No. 320,069, now Patent No. 3,208,112. Divided and this application Oct. 16, 1964, Ser. No. 404,254

4 Claims. (Cl. 16488) This application is a division .of my copending application Ser. No. 320,069 filed Oct. 30,' 1963 now Patent No. 3,208,112.

This invention relates to a novel metho'dand apparatus for continuously casting metal.

One object of the invention is to provide an improved method and apparatus for casting metal whereby a skidding action is imparted to at least a portion of the operative mold surfaces defining an open ended casting passage.

Another object of the invention is to provide a casting method and apparatus wherein an improved technique is utilized for controlling the withdrawal .of the work metal from the effective mold passage.

Another object of the invention is to provide a novel metal casting method and apparatus wherein an improved technique is used for rapidly extracting heat from the work metal.

Other objects of the invention will become apparent as the disclosure progresses. I

In the drawings:

FIG. 1 is a sectional elevational view of one embodiment which illustrates the novel method and construction contemplated by the instant invention.

FIG. 1 illustrates a system wherein a skidding movement of one of the casting passage surfaces serves to form and rapidly extract heat from the work metal that is progressively moving through the casting passage. The work flow past the moving skid surface here bears some resemblance to the fluid flow phenomenon occurring in the hydrodynamic lubrication of a bearing. On a base 50 there are mounted spaced upright side frame members such as 51. Rotatably mounted on and between the side frame members is a tubular casting roll 52 having tubular roll necks such as 53. Rotatably mounted in said roll necks is a tubular impeller shaft 54 having secured to the central portion thereof and disposed within the tubular body portion of roll 52 a pair of radial arms such as 55 having outer ends that are interconnected by paddle members such as 56. The roll 52 is adapted to be rapidly driven in a counter clockwise direction 57 by suitable drive means such as chain drive 58 while the impeller shaft 54 is adapted to be rapidly driven in a clockwise direction 60 by other suitable drive means. The shaft 54 is formed along its central length portion with radial holes such as 61 so that cooling fluid introduced from the ends of the tubular shaft may flow through said holes 61 and into the inner body portion of the rolls 52 and be rotatably circulated by the impeller paddle members 56 at a high rate of speed around the inner cylindrical surface of the roll 52. The annulus 63 of coolant thus formed may be progressively evaporated by the casting operation and the vapor may be exhausted through apertures such as 64 formed through the radial end walls of roll 52. The high speed rotary motion and the resultant centrifugal force of the coolant relative to an inner surface of the roll will serve to continually wipe the inner surface of the roll 52 so as to remove vapor bubbles therefrom and thus maintain a very high coeflicient of heat transfer which in turn makes it possible to rapidly extract large amounts of thermal energy from the work metal being cast.

A casting member or block 70 is pivotally mounted on 3,338,295 Patented Aug. 29, 1967 a cross shaft 71 secured between the side frame members and is formed with 'a concave arcuate surface 72 which is opposed to and cooperates with the adjacent portion of the casting roll to thereby form an arcuate open ended casting passage. The block 70 is formed with suitable end flanges such as 73 which closely embrace the adjacent roll ends so as to complete the closed sectional profile of the casting passage of the mold means. The block 70 is rotatably biased by means of a weight 74 so that the nose portion 75 of the block is constantly urged toward the adjacent lower surface of the casting roll 52, the limit of such biased movement being determined by a frame stop 76. The casting block 70 is formed with an inlet passage 77 so that work metal may be continuously supplied to the upper end of the casting passage. Mounted .on and be-. tween the side frame members is a run out table or support 80 and a pair of rotatably supported tension rolls 81, 82 that are adapted to be driven by a variable speed motor 83 through suitable gearing 84. A conventional type speed control unit 85 is provided for motor 83 and this control unit is operated by a conventional type transducer 86. Transducer 86 has an input control member or rod 87 which is connected to the block 70 so as to partake of any vertical displacement experienced by the said block nose portion 75. As the upper surface of the block nose portion moves towards or away from the adjacent surface of roll 52 the transducer 86 will change its output signal so as to cause motor 83 to slow down or speed up respectively.

In operation molten metal 90 or the like is introduced through inlet 77 and into the casting passage where it immediately experiences the influence of the rapidly moving outer surface of the cooling and forming roll 52. The fluid pressure in the work metal will increase and the increased pressure of the skidding contact between the metal and the said outer surface of roll 52 will improve the heat transfer rate and will cause the Work metal to be rapidly hardened, this hardening serving to further increase the heat transfer rate. The outer skid surface of roll 52 is continually cooled by said high speed annulus of spinning coolant 63 inside the spinning roll so that the work metal in arriving at the terminal portion of the casting passage will be formed and hardened sufliciently to be self supporting and will run out onto table 80 and between the driven rolls 81, 82; the latter providing a major impetus to the flow of work metal through the casting passage. The rates of solidification of the work metal may vary from time to time and this will be reflected in a pivotal movement of the block 70 which in turn through transducer 86 will appropriately adjust the speed of motor 83 to bring the casting rate back to within a predetermined desired mass flow rate range. The peripheral speed of the casting roll 52 is much greater than the linear speed of the cast strip or web 91 in the order of 50 to 1 and hence very large temperature differentials are possible between the work metal and the outer walls of the tubular casting roll 52 as well as between the coolant and the inner Walls of roll 52. Block 70 may be replaced either by a swing ably biased flanged roller; or an endless belt having a portion thereof wrapped around and spaced a uniform distance from a part of the periphery of roll 52, said belt extending around suitable pulleys and having spaced flexible refractory flanges longitudinally secured thereto for maintaining the uniform spacing between the belt and roll periphery and for closing the sectional profile of the casting passage.

While one embodiment of the invention has been shown and described, it will be apparent to those skilled in the art that numerous variations and modifications may be made in the particular construction without departing from the underlying principles of the invention. It is therefore desired by the following claims to include with in the scope of the invention all such variations and modifications whereby substantially the results of the invention may be obtained by the use of substantially the same or equivalent means and/ or steps.

The invention claimed is: 1. A method of continuously casting work metal; comprising the steps of providing a supply of work metal to a casting station; confining the flow of said work metal through said station to a predetermined open ended casting passage; and imparting a high speed movement to at least a portion of the surface defining said passage so that substan tial skidding movement occurs between said moving surface portion and the adjacent surface of the work metal in said passage whereby the work metal may be progressively formed and hardened to a predetermined sectional configuration while moving through said casting passage. 2. The method defined by claim 1; additionally comprising applying tension to the work metal leaving said casting station to control the mass rate of flow of cast work metal from said casting passage. 3. A method of continuously casting metal: comprising the steps of establishing a casting passage through which work metal may pass in being cast; supplying work metal to one end of said passage; and rapidly swinging at least one portion of the casting surface effectively defining said casting passage so that said surface portion partakes of a high speed wiping action over the adjacent side of the work metal in said casting passage whereby the said work metal may be progressively cast before leaving said casting passage.

4. A method of continuously casting metal: comprising the steps of placing a casting roll and at least one other casting member in juxtaposition, the outer operative casting surfaces of said roll and member being cooperatively disposed so as to effectively define at least a portion of a casting passage through which work metal may pass in being cast;

supplying work metal to one end of said casting passage; and

rapidly spinning said casting roll so that its said outer casting surface skids at high speed over the adjacent surface of the work metal moving through said casting passage whereby said work metal may be progressively cast before leaving said casting roll surface.

References Cited UNITED STATES PATENTS 441,643 12/1890 Close 164-276 2,301,902 11/1942 Merle 16486 3,047,915 8/1962 Barnard et al. 164-454 3,208,112 9/1965 Scribner 16483 FOREIGN PATENTS 519.977 4/ 1940 Great Britain.

J. SPENCER OVERHOLSER, Primary Examiner.

R. S. ANNEAR, Assistant Examiner. 

1. A METHOD OF CONTINUOUSLY CASTING WORK METAL; COMPRISING THE STEPS OF PROVIDING A SUPPLY OF WORK METAL TO A CASTING STATION; CONFINING THE FLOW OF SAID WORK METAL THROUGH SAID STATION TO A PREDETERMINED OPEN ENDED CASTING PASSAGE; AND IMPARTING A HIGH SPEED MOVEMENT TO AT LEAST A PORTION OF THE SURFACE DEFINING SAID PASSAGE SO THAT SUBSTANTIAL SKIDDING MOVEMENT OCCURS BETWEEN SAID MOVING SURFACE PORTION AND THE ADJACENT SURFACE OF THE WORK 